Page 35
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WARNING
Risk of electrical
shock! Use extra
care when making
electrical connec-
tions or performing
electrical tests.
5 Ampere Circuit Breaker:
This circuit breaker is a
single pole, manual reset, thermally-operated circuit
protection device rated at 5 amperes that protects a
circuit from being overloaded beyond the safe
current carrying capacity of the circuit. When the
breaker heats up to a certain temperature, it inter-
rupts the source of current and, when the cause of
the overload is corrected and it cools back down, it
may be reset to provide current.
External Electrical “Up/Fold” Solenoid:
When
the platform is below floor level, pressing the UP
switch energizes this solenoid. The solenoid directs
current to the pump motor which powers the hydrau-
lic pump to raise the platform. The Up/Fold
microswitch is activated when the platform reaches
floor level. This interupts the UP control switch
circuit which de-energizes the solenoid and removes
current to the pump motor and stops the platform.
Releasing the UP switch will also de-energize the
solenoid removing current to the pump motor and
stopping the raising function.
Pressing the FOLD switch then energizes the Up/
Fold solenoid through the fold circuit. The solenoid
in turn directs current to the pump motor to fold the
platform. Releasing the FOLD switch de-energizes
the solenoid removing current to the pump motor
and stopping the folding function.
Note:
When the platform reaches the stowed (fully
folded) position, the Hydraulic Platform Sensor
Pressure Switch is activated (minimum pressure
reached). The activated Pressure switch shuts the
pump moter off also. See page 41 for further details.
M268 Solenoid/Hydraulic Valves:
L915 lift models
are equipped with the M268 hydraulic pump (further
details in Hydraulic section). The M268 features
pump-mounted
Unfold
,
Bridging
and
Down
solenoid/hydraulic valves (details follow).
When the platform is in the stowed (fully-folded)
position, pressing the UNFOLD switch energizes all
three solenoid/valves. When the platform reaches
floor level, the solenoid/valves are de-energized by
the Unfold/Down microswitch circuit. Releasing the
UNFOLD switch also de-energizes the solenoid/
valves.
The Bridging and Down solenoid/hydraulic valves
are also energized while the DOWN switch is
pressed when the platform is fully unfolded. Both
solenoid/valves will remain energized until the
DOWN switch is released.
Note:
The Bridging solenoid/hydraulic valve will
remain energized until the DOWN switch is released
or
the Bridging microswitch is deactivated. Deacti-
vation of the Bridging microswitch stops the down
travel of the platform while allowing the roll stop to
deploy.
Troubleshooting: A problem with the solenoid/
valves can be electrical or hydraulic. Follow the
Quick-Check
troubleshooting procedure when
troubleshooting.
Quick-Check:
Read warning
posted at right!
Remove all rings,
watches, etc. prior to
doing any electrical
work near the pump
motor.
With the lift stowed,
hold a paper clip (or
other magnetically
attracted object)
near the center
threaded post on the
solenoid/valve while
pressing the UN-
FOLD switch (
stand
clear of platform
).
If the solenoid post does not magnetically attract the
paper clip, there is an electrical problem. If at-
tracted, there is a hydraulic problem.
Note:
If this solenoid post is bent at all, the hydrau-
lic valve will not operate.
